[pstricks] Problem with pst-tree and beamer

[Alan Ristow]

Hi all,

When I run the minimal example below I get the following error:

! Illegal parameter number in definition of \test.
<to be read again>
                    1
l.10 \end{frame}

The PSTricks part of the code is copied straight from pst-user.pdf and 
works fine outside of the frame environment -- it is only when I place 
it between \begin{frame} and \end{frame} that the error comes up.

Any ideas?

Alan


\documentclass{beamer}
\usepackage{pst-tree}

\begin{document}
\begin{frame}
   \psset{armB=1cm, levelsep=3cm, treesep=1cm,
     angleB=-90, angleA=90, arrows=<-, nodesepA=3pt}
   \def\psedge#1#2{\ncangle{#2}{#1}}
   \pstree[radius=2pt]{\Ttri{root}}{\TC* \TC* \TC* \TC*}
\end{frame}
\end{document}